Here is the full list of all 24 Lethal VR achievements.
Get a rating for the Agent Simulation
Score a Triple Bullseye
Get a rating with the Razor Tipped Hat
Perform your first Perfect with any weapon
Get a rating for the Recruit Simulation
Get a rating with the Throwing Star
Score a Double Headshot
Get a rating for the Amateur Simulation
Get a rating with the Dundee Knife
Get a rating for the Beginner Simulation
Get a rating with the Gold Plated Gun
Score a Quick Draw rating
Score your first headshot
Score a Fast Draw rating
Score a Bullseye with a knife
Score a Double Bullseye
Score a rating on every Round
Score a Triple Headshot
Shoot a bullseye and a headshot into a single target
Perform your first double Perfect
Get 10 Lethal Ratings
Get a rating for the Rookie Simulation
Get a rating with Harry's Gun
Get a rating with the OCP Gun